Aim
During early post‐natal development, arterial contraction depends less on Ca2+‐signalling pathways but more on changes in Ca2+‐sensitivity compared to adult animals. Whether this difference is ...related to Rho‐kinase, one of the major players affecting Ca2+‐sensitivity, is unknown for intact vessels. Thus, we tested the hypothesis that Rho‐kinase critically contributes to the higher Ca2+‐sensitivity of contraction in intact arteries of 1‐week‐old rats.
Methods
We studied 1‐week‐old, 4‐ to 5‐week‐old and 10‐ to 12‐week‐old rats performing isometric myography, Ca2+‐fluorimetry and Western blotting using intact saphenous arteries and arterial pressure measurements under urethane anaesthesia.
Results
In 10‐ to 12‐week‐old rats, methoxamine (MX) produced vasoconstriction associated with an increase in Ca2+i and Ca2+‐sensitivity. In contrast, in 1‐week‐old rats these contractions were accompanied only by an increase in Ca2+‐sensitivity. All MX‐induced effects were reduced by the Rho‐kinase inhibitor Y‐27632; this reduction was complete only in 1‐week‐old rats. The Rho‐kinase specific site Thr855 on MYPT1 was increasingly phosphorylated by MX in vessels of 1‐week‐old, but not 10‐ to 12‐week‐old rats; this effect was also inhibited completely by Y‐27632. The Rho‐kinase inhibitor fasudil in a dose not affecting the pressor response to MX in 4‐ to 5‐week‐old rats reduced it considerably in 1‐week‐old rats.
Conclusion
Our results suggest that the higher Ca2+‐sensitivity of arterial contraction in 1‐week‐old compared to 10‐ to 12‐week‐old rats is due to a greater Rho‐kinase activity. Constitutively active Rho‐kinase contributes to MX‐induced contraction in 10‐ to 12‐week‐old rats. In 1‐week‐old rats, additional Rho‐kinase activation is involved. This remodelling of the Rho‐kinase pathway is associated with its increased contribution to adrenergic arterial pressure responses.
Aim
A decrease in the Ca2+ sensitivity of smooth muscle contraction is a hallmark of functional remodelling of blood vessels during development. However, the responsible factors are largely unknown. ...Here, we tested the hypothesis that the post‐natal decline of arterial Ca2+ sensitivity is the result of trophic effects of sympathetic nerves.
Methods
Contractile responses, intracellular Ca2+ levels and protein expression profiles were compared in saphenous arteries from young (1‐ and 2‐week‐old) and adult rats using wire myography, Ca2+ fluorimetry and Western blotting respectively.
Results
We observed a lower Ca2+ sensitivity of contractions induced by methoxamine, an agonist of α1‐adrenoceptors, and U46619, an agonist of thromboxane A2 receptors, in arteries from adult as compared to young animals. Post‐natal maturation was associated with stronger expression of regulatory proteins mediating Ca2+‐dependent contraction (myosin light chain kinase (MLCK), myosin targeting subunit (MYPT1) and h‐caldesmon) and weaker expression of proteins regulating Ca2+‐independent contraction (Rho kinase, extracellular‐regulated kinases (ERK1/2) and mitogen‐activated protein kinases p38 MAPK) in vessels from adult rats. To eliminate the trophic action of sympathetic nerves, we performed lumbar sympathectomy in adult rats. This resulted in higher Ca2+ sensitivity of agonist‐induced contractions in denervated as compared to control arteries. Furthermore, denervated arteries contained less MLCK, MYPT1 and h‐caldesmon and more ERK1/2 and p38 MAPK.
Conclusions
Sympathetic denervation reverses developmental changes both in Ca2+ sensitivity and in the expression of regulatory proteins back to the early post‐natal phenotype in the rat saphenous artery. We conclude that trophic effects of sympathetic nerves govern functional remodelling of arteries during early post‐natal development.
We present an optical-to-radio study of the BL Lac object S4 0954+658 observations during 1998–2023. The measurements were obtained with the SAO RAS Zeiss-1000 and AS-500/2 0.5-m telescopes in ...2003–2023, with the RATAN-600 radio telescope at 1.25 (0.96, 1.1), 2.3, 4.7 (3.7, 3.9), 8.2 (7.7), 11.2, 22.3 (21.7) GHz in 1998–2023, with the IAA RAS RT-32 Zelenchukskaya and Badary telescopes at 5.05 and 8.63 GHz in 2020–2023, and with the RT-22 single-dish telescope of CrAO RAS at 36.8 GHz in 2009–2023. In this period the blazar was showing extremely high broadband activity with the variability amplitude of the flux densities up to 70–100
both in the optical and radio domains. During the period of 2014–2023 the blazar displayed extremely high activity in the radio wavelengths, and we detected multiple radio flares of varying amplitude and duration. The large flares last on average from 0.3 to 1 year at 22–36.8 GHz and slightly longer at 5–11.2 GHz. The optical flares are shorter and last 7–50 days. The characteristic time scale
of variation at 5–22 GHz is about 100 days in the most active epoch of 2014–2023 and about 1000 days for the state with lower activity in 2009–2014. We found a general correlation between the optical, radio, and
-ray flux variations, which suggesting that we observe the same photon population from different emission regions. We estimated the linear size of this region as 0.5–2 pc for different conditions. A broadband radio spectrum with two components of the S4 0954+658 jet was modeled using both electrons and protons as emitting particles. The results suggest that the synchrotron radio waves in this AGN may be produced by relativistic protons.
Study of high-redshift radio galaxies (HzRGs) can shed light on the active galactic nuclei (AGNs) evolution in massive elliptical galaxies. The vast majority of observed high-redshift AGNs are ...quasars, and there are very few radio galaxies at redshifts
. We present the radio properties of 173 sources optically identified with radio galaxies at
with flux densities
mJy. Literature data were collected for compilation of broadband radio spectra, estimation of radio variability, radio luminosity, and radio loudness. Almost 60
of the galaxies have steep or ultra-steep radio spectra; 22
have flat, inverted, upturn, and complex spectral shapes, and 18
have peaked spectra (PS). The majority of the PS sources in the sample (20/31) are megahertz-peaked spectrum source candidates, i.e. possibly very young and compact radio galaxies. The median values of the variability indices at 11 and 5 GHz are
and
, which generally indicates a weak or moderate character of the long-term variability of the studied galaxies. The typical radio luminosity and radio loudness are
erg s
and
respectively. We have found less prominent features of the bright compact radio cores in our sample compared to high-redshift quasars at
. The variety of the obtained radio properties shows the different conditions for the formation of radio emission sources in galaxies.
A decrease in the Ca(2+) sensitivity of smooth muscle contraction is a hallmark of functional remodelling of blood vessels during development. However, the responsible factors are largely unknown. ...Here, we tested the hypothesis that the post-natal decline of arterial Ca(2+) sensitivity is the result of trophic effects of sympathetic nerves.
Contractile responses, intracellular Ca(2+) levels and protein expression profiles were compared in saphenous arteries from young (1- and 2-week-old) and adult rats using wire myography, Ca(2+) fluorimetry and Western blotting respectively.
We observed a lower Ca(2+) sensitivity of contractions induced by methoxamine, an agonist of α1 -adrenoceptors, and U46619, an agonist of thromboxane A2 receptors, in arteries from adult as compared to young animals. Post-natal maturation was associated with stronger expression of regulatory proteins mediating Ca(2+) -dependent contraction (myosin light chain kinase (MLCK), myosin targeting subunit (MYPT1) and h-caldesmon) and weaker expression of proteins regulating Ca(2+) -independent contraction (Rho kinase, extracellular-regulated kinases (ERK1/2) and mitogen-activated protein kinases p38 MAPK) in vessels from adult rats. To eliminate the trophic action of sympathetic nerves, we performed lumbar sympathectomy in adult rats. This resulted in higher Ca(2+) sensitivity of agonist-induced contractions in denervated as compared to control arteries. Furthermore, denervated arteries contained less MLCK, MYPT1 and h-caldesmon and more ERK1/2 and p38 MAPK.
Sympathetic denervation reverses developmental changes both in Ca(2+) sensitivity and in the expression of regulatory proteins back to the early post-natal phenotype in the rat saphenous artery. We conclude that trophic effects of sympathetic nerves govern functional remodelling of arteries during early post-natal development.
During early post-natal development, arterial contraction depends less on Ca
-signalling pathways but more on changes in Ca
-sensitivity compared to adult animals. Whether this difference is related ...to Rho-kinase, one of the major players affecting Ca
-sensitivity, is unknown for intact vessels. Thus, we tested the hypothesis that Rho-kinase critically contributes to the higher Ca
-sensitivity of contraction in intact arteries of 1-week-old rats.
We studied 1-week-old, 4- to 5-week-old and 10- to 12-week-old rats performing isometric myography, Ca
-fluorimetry and Western blotting using intact saphenous arteries and arterial pressure measurements under urethane anaesthesia.
In 10- to 12-week-old rats, methoxamine (MX) produced vasoconstriction associated with an increase in Ca
and Ca
-sensitivity. In contrast, in 1-week-old rats these contractions were accompanied only by an increase in Ca
-sensitivity. All MX-induced effects were reduced by the Rho-kinase inhibitor Y-27632; this reduction was complete only in 1-week-old rats. The Rho-kinase specific site Thr
on MYPT1 was increasingly phosphorylated by MX in vessels of 1-week-old, but not 10- to 12-week-old rats; this effect was also inhibited completely by Y-27632. The Rho-kinase inhibitor fasudil in a dose not affecting the pressor response to MX in 4- to 5-week-old rats reduced it considerably in 1-week-old rats.
Our results suggest that the higher Ca
-sensitivity of arterial contraction in 1-week-old compared to 10- to 12-week-old rats is due to a greater Rho-kinase activity. Constitutively active Rho-kinase contributes to MX-induced contraction in 10- to 12-week-old rats. In 1-week-old rats, additional Rho-kinase activation is involved. This remodelling of the Rho-kinase pathway is associated with its increased contribution to adrenergic arterial pressure responses.
Mesoporous nanosized xerogels and powders in the system ZrO2–Y2O3 are obtained by two techniques, including co-precipitation of hydroxides and micromixing in a microreactor with impinging swirled ...flows (MRISF). The phase composition, surface characteristics, microstructure and textural features of the prepared xerogels and powders are studied. Compared with the conventional co-precipitation procedure, MRISF technique provides xerogels with improved performances, including significantly lower hydrodynamic diameter, ζ-potential and agglomeration of the particles, probably due to a reduced content of active centers on their surface and high level of shear stresses in the course of the synthesis. Furthermore, the developed MRISF is shown to provide a continuous high-throughput process advantageous in respect of easy numbering-up instead of the conventional scaling-up. Particularly, the lab-scale MRISF device used in this study affords a daily output of the slurry up to 8.5 m3 yielding 200–300 kg/day of the target nanosized particles.
The paper presents the stages of constructing a vector autoregression model (VAR model) for forecasting inflation at the regional level and implements a short-term inflation forecast for the Novgorod ...region. For this purpose, the selection of possible indicators (20 units) for the VAR model was carried out, the need for their use was economically justified. As a result, 4 indicators were used for the VAR model. The explanatory variables included the following ones: Price indices of producers of agricultural products sold by agricultural organizations (products and services of agriculture and hunting); Re-tail turnover of non-food products, %; Average monthly real accrued wages of employees of organizations, %. The exoge-nous variable was the Index of the real exchange rate of the ruble to the US dollar, %. The necessity of using dummy varia-bles to eliminate the impact of the identified shocks in the dynamics of inflation was also justified: the impact of the shocks of 2014–2015, when the Bank of Russia announced a floating exchange rate and started targeting inflation, was eliminated, as well as the shock of March 2022, when geopolitical instability intensified, which resulted in a short-term weakening of the ruble and a surge in consumer demand. The resulting VAR model was found to be consistent after carrying out all the necessary econometric tests. The model was verified. Based on the simulated VAR model, a short-term inflation forecast for the Novgorod region was constructed. Subsequently, it was decided to adjust the resulting forecast series of inflation based on the available data of the non-monetary inflation factor. It is worth noting that the developed VAR model is suitable only for the subject of the Russian Federation, selected in the study, since each region of Russia is unique, therefore, the selec-tion of indicators should be carried out for each territory individually. At the same time, the algorithm for constructing a orecasting model is universal and can be applied to various territories. As a result, it has been concluded that it is im-portant to construct an inflation forecast, since its impact must be taken into account in financial planning by absolutely all economic agents at all hierarchical levels including the government, business and citizens.
PDF
